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        <title>Document</title>
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    <body>
        <script>
            let srt1 = "hi tom";
            console.log(srt1.replace("tom", "wangyu"));
            let srt2 = ["2022", "08", "22"];
            let srt3 = srt2.join("-");
            console.log(srt3);
            const str8 = "   hello world   ";
            console.log(str8.trim());
        </script>
        <script>
            const arr = [1, 2, 3, 4];
            console.log(arr.includes(4));
            console.log(arr.includes(8));
            const str = "hello world";
            console.log(str.includes("hello"));
            console.log(str.includes("to"));
        </script>
    </body>
</html>
